Refrigerating process and apparatus



July 1, 1930.v Rw. DAVENPQRT- 1,769,017v

REFRIGERA'IING PROCESS AND APPA'RATUS Filed Nov. so.' 192e l l I l JNVENTOR. Y Pansa/27 h /az/e//p/'t ATTORNEY I Patented Jul! 1936 4 .UNITED STATI-:s PATENT orner.

BANSOM W@ DAVENPORT, OF DETROIT, MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC i T0012 COMPANY, OIF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY nErme-Em'rme rnoonss Ann Arraaa'rrrs Application led November 30, 19'26. Serial No. 151,671.

i This invention relates to the transforming of heat with particular reference to refrigerating systems of the closed cycle type 4 utilizing as a Working substance a solution [5 of lubricant ina volatile liquid, the soluv tion being of the general type disclosed and claimed in my copending application Serial No. 60,311, filed October 3, 1925,. The 1nvention comprises bothV a process and apparatus for'practcing the process, and in certain respects may be considered as an improvement upon and further development of the process disclosed in my copending application, lSerial No. 85,580, filed February i 2nd, 1926, Patent No. 1,698,938, dated January 15,1929.

One object of theinvention is to devise improved-ways and means for effecting the concentration of the solution and movement 20 ofthe concentrate to the parts requiring lubrication. Other objects will be a parent from the detailed description which ollovvs: The invention provides for'accomplishing the concentration vof the solution'in a multiplioity of steps or stages,.each differing but slightly in vdegrees of concentration from the adJoining steps or stages, thereby to effect a more.J uniform and higher concentration. To this end any desired nmberof 3o small bodies of the solution, preferably many, are retained'on the -low side of the sysv tem, `as in the refrigerating. element, under the suction pressure of the pump or compresceive freshincrements of solution from preceding or less concentrated bodies, retaining- 59 drawings, in which:A

sor. From time tov time these bodies re- Fig. 1 is a diagrammatic view of a closed cycle system; and

Fig. 2 is a perspective view of a self-contained refrigerator for household use.

As dia rammatically shown inFig'. 1, ap-

paratus or practicing my improved process may comprise an eva orator element A,

and a feeding dea pump B, a condenser vice D connected together `to form a closed circuit for the solution of volatileliquid and lubricant comprising the Working substance. The compressor, the condenserand the feeding device may be of any known or suitable 4type since the securing of the required concentration of lubricant is effected by my improved process in the evaporator element. The vaporizing of the volatile component `of the working substance is accordingl accomplished in an evaporator element di ering in certain important respects from elements of the conventional type. The element may be made in a variety of forms, it being essential merely that it proy vide pockets or traps in Whlch relatively s small bodies of the refrigerating solution are retained under the suction pressure of the com ressor while movement of the solution is e ected toward the compressor and backilow prevented.

The evaporator element A shown for illustration only and not by W'ayof limitation, comprisesa riser 'ay extending above feeding device D and a down comer nl above compressor B. The riser and the down comer may be 'formed of coils of pipe having return bends at a? forming loops, pockets, or

traps for the solution, the-riserand the down.

comer beingconnected. across the top by a pipeY as. With the evaporator shown the risera is nearly or quite filled with the solution of the volatile liquid and lubricant forming the working substance which passes from time to time in small quantities into the down comer a as more solution is added through the feeding device D. This movement of the solution to the down comer will take 'place particularly at the times when the compressor B is started. The result is that the loops a in the down comer a contain bodies of the solution in a. partly conloo centrated form and are retained for a considerable period under the suction pressure of compressor B. Then as a fresh increment r: of solution passesl from the riser a into the 5 down comer a a portion of the liquid body in the first pocket of the down comer is dis.- placed and passes on to the second pocket, this process continuing progressively so that solution of greater and greater concentration is washed from stage to stage of concentration until practically undiluted, lubricant passes to compressor B to be utilized to prevent wear of the moving parts thereof. The lubricant is then discharged by com- V.pressor B along With the vapor of the volatile component of the solution, which has been Withdrawn from evaporator A, into condenser C Where the vapor is condensed and again dilutes the lubricant forming the dilute solution which is again fed through feeding device D.

The movement of the solution from the riser to the down comer and through the stages of the latter is more definite and certain When the apparatus is arranged to employ the vapor-gas principle disclosed in my copending application, Serial No. 15,172, filed March 12, 1925, Patent No. 1,619,196, March 1, 1927, since the expansion of the gas up through the liquid in riser tends to move the liquid toward the dovvn comer a and prevents backfiow from the latter. With the form of evaporator element shown, it is apparent that the riser 'part alone Will operate on the vapor-gas principle and that the down comer will operate by straight suction as in systems of the conventional type. As previously stated other types of evaporater devices may be employed, provided they have means for trapping many small bodies of solution since the form isimmaf terial so long as they embody the principle of the invention which lies in the retention, evaporation and moving ahead of small bodies of solution in successive cycles each time the system is started into operation and preventing backfiow each time it is stolpped. n Fig. 2 is 'disclosed a self-contained household fiefrigerator outfit adapted to operate on the principle previously de scribed. The outfit comprises the refrigerator cabinet 3, having a food storage compartment 4, and a machine compartment 5 disposed beneath the refrigerator compartment 4. The means for extracting heat from refrigerating` compartment 4 may comprise an evaporator. element similar to that shown in Fig. 1 compris' riser 6 formed of a return-bent coil; disposed against one inner wall of -thef 'inpartment and a down comer 7 formed ofasimilarly return-bent coil of pipe against another Wall of the compartment, such as the opposite wall, these 65 parts 'of the evaporator element being interconnected across the top by a pipe 8. The

refrigerating compartment 4 may also contain means for the freezing of liquids, as Water'into ice cubes, such as a cold box` 9 in series with riser 6 and down comer 7, these parts together forming the evaporator element. The cold box 9 may contain drawersy 9 for trays for water or other liquid to be frozen. The down comer 7 connects by a pipe 10 with the inlet ofthe compressor part of a motor pump unit 11 disposed in machine compartment 5, the discharge of the pump or compressor portion. being through a pipe 12 leading to a condenser 13 of any suitable or desired type In the present instance the condenser comprises a coil of pipe secured to the exterior of refrigerator 3 as at the back, and arranged to be cooled by natural draft. Condenser 13 drains into a feeding devicelef by which the products of the condenser are directed into the base of cold box 9. The outfit shown in Fig. 2 is arranged to utilize a lubricating refrigerant operating on the vapor-gas principle previously referred to, and the solution concentrated by its pasasge through the stages of the down comer 7 until it is practically in the form of pure lubricant, is

.arranged to pass into the motor pump unit 11 by gravity, as also indicated in Fig.,1, to lubricate the Working parts thereof. While both the process and the apparatus aspects of the invention land the manner of operation have been herein illustrated in what are noW considered to be their preferred for/ms, it is to be understood that the invention is not limited to the specific details thereof but covers all changes, modifications and adaptations Within the scope of the appended claims.

I claim as my invention: l

1. In a closed cycle .system utilizing a liquid solution lcontaining a non-volatile component as the Working substance the process of refrigeration which comprises 110 circulating the solution through the system to producev thermodynamic effects and retaining bodies of the solution at one point of the cycle under suction pressure to drive ofi' the volatile part of said .solution and 115 progressively concentrate the non-volatile part.

`2. In a closed cycle system utilizing a liquid solution containing lubricant as a Working substance, the refrigerating .process which includes the step of subjecting a body of the solution to suction pressure to vaporize vthe volatile parts thereof with an absorption of heat, and separating out and retaininga Aseries of bodies of the solution f 3. In a closed *cycle system utilizing a liquid solution containing lubricant as a absorption ofheat, and 'moving the solution through a'series -of separated bodies of the same to effect progressive concentration ofv the lubricant.

4. In a closed cycle `system utilizing a' liquid solution containing lubricant as a Working substance, the refrigerating process which includes the step of subjecting the solutionin a series of bodies to suction pressure to vaporize the volatile parts thereof with an absorption of heat, and intermittently moving a portion of the solution in each of'said series of bodies to the lnext lbody to eect progressive concentration of the lubricant.

ess which comprises disposing the solution in the 10W side of the system in a series of bodies subjected to vsuction pressure to vaporizethel volatile component and absorb .heat and concentrate the lubricant in said Y bodies, moving the solution by gravity from one body to the next to effect a progressive and high concentration of the lubricant, utilizing the concentrate for lubrication, ex-

, tracting heat from the vaporized component on the high side of the system to condense the same and dilute the concentrate, feeding the dilute solution back to the lovir side, and continuously repeating the above steps.

6.v In a closed cycle system utilizing a solution of a volatile liquid and a lubricant as a Working substance, the refrigerating process which comprises disposing the solution on the lovv side ofthe system in a series of bodies subjected -to suction pressure to vaporize the volatile componentand absorb heat and concentrate the lubricant in said bodies, intermittently moving the solution in limited amount by gravity from one body to the next to effect a progressive and high Vconcentration of the lubricant, utilizing the culation of the ,Working substance together' (i0` concentrate for-lubrication, extracting heat from the vaporized component on the high side of the system to condense the same and dilute the concentrate, feeding the dilute solution back to the low side and'continuously repeating the abovesteps.

\ 7. `In 'a clbsed` cycley system utilizing asa Working substance a solution'of a volatileliquid and a lubricant, the process of refrigeration which comprises forcing the cir- With an inert and incondensible gas through the cycle with vaporization of the volatile liquid'and absorption of heat on the low side and' condensation ofthe vapor with ejection of heat on the high side, and effecting concentration of thesolution on the low side for lubricating purposes by. disposing the solution in a plurality of bodies subjected to suction pressure to produce stages of concentration, and utilizing the feeding of inert gas and solution from the high side of the cycle to the low side to eHect progressive ymovement of the solution in one direction only through said bodies.

8. In a closedcycle system utilizing as a Working substance a solution of a volatile liquid and a lubricant, the process ofl refrigeration which comprises forcing the circulation of the Working substance together.

With an inert and incondensible gas through the cycle with vaporization of the volatile liquid and absorption of heat' on the love7 side and condensation of the vapor with ejection of heat on the high side, and effecting concentration of the solution on the loW side for lubricating purposes by disposing the solution in a plurality of bodies at progressively lower levels as the source of suc'- tion pressure is approached to produce stages of concentration, and utilizing the feeding of inert. gas and solution from the high side of the cycle to the low side to effect progressive movement of the concentrating solution in one direction only through said bodies.

9. In combination, a compressor, ai condenser, and an evaporator connected togeth er-to form a closed cycle system utilizing a lubricating refrigerant, said evaporator havingmeans for moving the refrigerant solu- -tion in stages of ,progressively greater concentration to said compressor.

l0. In combination, a compressor, a condenser, andan evaporator connected together to form a closed c cle refrigerating system, said evaporator eing adapted and arranged to contain as a Working substance for said system a solution of a volatile liquid and a' lubricant and having means disposing at least a portion of said solution in separate bodies maintained against back flow, means for moving the solution progressively through. said bodies for securing a high concentration of lubricant, and means passing the concentrate by gravity to said compressor. y

11. In combination, a compressor, a condenser and an evaporator connected together tof form a closed cycle refrigerating system, said evaporator being adapted and arranged t contain as a Working substance for said system a solution of a volatile liquid and a lubricant, said evaporator providing c pockets in the path of movement of thel ity through said bodies -to"fsaid compressor.

12. In combination, acompressor, a con-` denser and an evaporator connected together to form a closed cycle refrigerating system, said evaporator being adapted and arranged to contain as a working substance for said system a solution of a volatile liquid and a lubricant, said evaporator providing a series of pockets for said solution at progressively lovver levels whereby the solution may pass by gravity from one pocket to the next toward said compressor and a gravity connection from lthe last pocket of said evaporator to said compressor.

13. Refrigerating apparatus forming a closed circuit for utilizing a lubricating refrigerant and for concentrating the same on the lovv pressure side of the system comprising an evaporator, a compressor, and a condenser, said evaporator comprising rising and dovvncoming parts, means in one of said parts for disposing liquid refrigerant in a plurality of bodies subjected to lthe suction pressure of said compressor, and means for moving the liquid refrigerant progressively from body to body to concentrate the lubricant component thereof and thence to said compressor. l

14. Refrigerating apparatus forming a closed circuitcomprising an evaporator, a compressor, and a condenser, said evaporator being arranged to contain a liquid solution of volatile and non-volatile-components and having rising and down-coming parts, and means for vvashing7 the solution in stages of progressively 'greater concentration to said compressor comprising a series of pockets in said down-coming part.

15. In a refrigerating system of the closed circuit type, an'evaporator for containing a lubricating refrigerant, said evaporator comprisinga -riser and a down comer, and means for operating the riser part of said evaporator on the 'vapor-gas principle and for operatin the down-comer part on the straight suctlon principle.

16. I n a refrigerating system of the closed circuit type, an evaporator for containing a lubricating refrigerant, said evaporator comprising a riser and a dovvn comer, means for operating the riser part of said evaporator on .the vapor-gas principle and for operating the down-comer part on the straight suction'` principle, and means for producing progressive concentration of the lubricatingp refrigerant in said down-comer part.

17. In a refrigerating system of the closedcircuit type, an evaporator for containing a lubricating. refrigerant, said evaporator comprising a riser and a down comer, means for operating the riser part of said evaporator on the vapor-gas principle and for operating the down-comer part on the-straight suction principle,and .means for producing progressive concentration of the lubricating refrigerant in said down-comer part including a series of pockets for trapping and holding bodies o said refrigerant.

18. In a refrigerating system of the closed circuit type, an evaporator for containing a lubricating refrigerant, said evaporator comprising a riser and a down comer, means for operating the riser part of said evaporator on the vapor-gas principle and for operating the down-comer part on the Istraight suction principle, and means for producing progressive concentration of the lubricating refrigerant in said down-comer part including a series of pockets at progressively lower levels for trapping and holding bodies of refrigerant and permitting overflow of each lbody to pass by gravity to the next lovvery body.

19. A self-contained refrigerator of the mechanically operated type utilizing a lubricating refrigerant and having a refrigerating compartment, an evaporator disposed in said compartment to extract heat therefrom, said evaporator comprising a. freezing unit, a riser and a dovvn comer connected in series and arranged to effect concentration of the non-volatile or lubricant component of the refrigerant in said down comer, and means forming With said evaporator a closed-cycle system, said means including a compressor arranged to be lubricated by the lubricant concentrate of said evaporator.

20. A self-contained refrigerator 'of the 'mechanically operated'type having a refrigerating compartment, an evaporator disposed in said compartment to extract heat.

therefrom, said evaporator comprising a freezing unit, a riser and a dovvncomer connected in series, said `dovvn comer having pockets for the refrigerant solution, andmeans forming with said evaporator a closed cycle system utilizing a lubricating refrigerant and operating on the vapor-gas v principle, saidl means including a motorpump unit disposed beneath said compartment into which the concentrated lubricant Washed through said down comer may v pass by gravity to lubricate said unit.

21. An evaporator element for effecting concentration of a liquid Working substance having volatile and non-volatile components comprising an outlet adjacent its base and a series of ockets for trapping and retaining bodies of 'the liquid working substance above said inlet and outlet.

a container having an inlet and 22. An evaporator element Ifor effecting concentration of a liquid working substance,

having volatile and nonvolatile components comprising a container having an inlet and an outlet adjacent its base and providing a series of recesses for ltrapping and retaining bodies of the lliquid working substance, said recesses being at ldifferent levels so that overiow from one .recess vmay pass bodies of a refrigerant solution so as to ef' fect progressively greater concentration of the solution and to pass the concentrated solution by gravity to said outlet. s

24. An evaporator element for refrigerating systems comprising a freezing unit, a riser, and a down comer connected in series, said element having an inlet adjacent the base of said unit and an outlet adjacent the base of said down comer, said element being arranged to permit a gradual Washing of a refrigerant solution in stages of progressively greater concentration to said outlet.

25. An evaporator element for refriger- I ating systems comprising a freezing unit, a

riser, and a down comerconnected 1n series, said element having an inlet adjacent the base of said unit and an outlet adjacent the base of said down comer, said down comer being formed of a conduit having return bends providing a series of pockets at progressively lower levels for trapping bodies of a refrigerant solution containing lubricant to elect a gradual washing of the solution in progressive stages of concentratlion from pocket to pocket toward said out et.

ASigned. by me at Detroit, in the county of Wayneand State of Michigan, this 27th day Vof November, 1926.

RAN SOM W. DAVENPORT. 

